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SWrucWural Analysis of HisWorical ConsWrucWions – Jerzy Jasieńko (ed) © 2012 DPNH ProcławH PolandH ISSN 0860-2395H ISBN 978-83-7125-216-7

PERFORMANCE OF NDTI MDT AND DT TECHNIQUES IN ASSESSING THE EFFECTIVENESS OF GROUTING rranjek jojmirNI Žarnić ookoOI Bokan-Bosiljkov sioletaPI Bosiljkov slatko4 ABSTRACT drout= injection= is= a= common= and= widely= used= method= for= seismic= strengthening= of= stone= masonry=walls= with= sufficient= amount= of= voidsK= eoweverI= the= influence= of= different= types= and= properties= of=grout =on =the =mechanical =properties =of =injected =wallsI =still =remains =the =area =which =requires =further =researchK= `onsequentlyI= a= stone= masonry= building= located= in= the= ruralI= earthquake-prone= area= of=mosočje= in=ploveniaI= was= subjected= to=several= in=situ= investigation= techniquesK=qhe=objective=was= to=evaluate= the= effectiveness= of= different= types= of= injection= grout= and= at= the= same= time= to= assess= the=usefulness= of= different= investigation= techniques= in= determining= the= quality= and= effectiveness= of=groutingK=pelected=parts=of=the=building”s=walls=were=strengthened=with=grout=injection=techniqueI=using=cement= and= combined= cement-lime= groutsK= tall= specimens= were= tested= in= their= existing-ungrouted=state=and=NUM=days=after=strengtheningK=bffectiveness=and=quality=of= grout= injectionI=assessed=by=non-destructiveI= minor=destructive=and=destructive= investigation=techniquesI=showed=that= the=combination=of= several= investigation= techniques= provides= better= insight= and= enables= more= reliable= assessment= of=strengthening= by= means= of= grout= injectionK= ft= was= also= found= that= the= mechanical= characteristics= of=strengthened=walls=significantly=depend=on=the=type=of=grout=EcementI=cement-limeF=used=for=groutingK= heywords: ptone masonryI ptrengtheningI drout injectionI drout typesI fn situ tests NK INTRODUCTION =jany=historical=buildings=in=plovenia=were=built=from=stoneI=or=as=mixed=stone=and=brick=assemblagesK=ptone=types=such=as=mixed=stone=and=limestoneI=sandstone=and=slate=were=usedK=lften=brick=intrusions=were=included=by=constructing=the=wallsK=qhicker=walls=were=constructed=in=three=layers=Eouter= layers=made=of=roughly=shaped=stones=and=inner=core=from=leftovers=and=smaller=stonesFI=while=thinner=walls=mainly= had= only= two= layersK= fn= general= low= strength= lime= mortars= with= the= limeWsand= volume=proportion=of=NWP=were=used=to=bind=the=stone=masonry=unitsK=Because=of=weak=connections=between=outer= leavesI= voids= and= the= low= strength= of= used= mortarI= the= load= bearing= capacity= of= such= wallsI=especially= towards= horizontal= loading= such= as= earthquakeI= is= usually= insufficientK= Among= different=techniques= for= the= improvement= of= this= type= of= masonry= such= as= repointingI= transversal= tyingI=reinforced-concrete= or= com= coatingI= grout= injection= may= be= the= most= appropriate= strengthening=techniqueK= qhis= is= especially= the= case= when= we= are= faced= with= the= requirements= regarding= the=preservation=of=the=original=appearance=of=stone=masonry=wallsK=Although=grout=injection=is=a=common=and=widely=used=method=for=seismic=strengthening=of= stone=masonry=walls=with=sufficient=amount=of=voidsI=the=influence=of=different=types=and=properties=of=grout=on=the=mechanical=properties=of=injected=wallsI =still =remains =the =area =which =requires =further =researchK =jost =of =the =authors =who =studied =the =strengthening=of= masonry=by=means=of=grout= injection= xN-PzI= agreeI= that= the=compressive=strength=of=================================================N=mhKaKI=mroject=janagerI=Building=and=`ivil=bngineering=fnstitute=wojhI=mojmirKuranjek]gi-zrmkKsi=O=mhKaKI=mrofessorI=rniversity=of=ijubljanaI=caculty=of=`ivil=and=deodetic=bngineeringI=rzarnic]fggKuni-ljKsi=P=mhKaKI=Associate=mrofessorI=rniversity=of=ijubljanaI=caculty=of=`ivil=and=deodetic=bngineeringI====vbokan]fggKuni-ljKsi=4=mhKaKI=Assistant=mrofessorI=rniversity=of=ijubljanaI=caculty=of=`ivil=and=deodetic=bngineeringI====vbosiljk]fggKuni-ljKsi=

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OR4R=

grout=injected=walls=is=not=directly=proportional=to=the=compressive=strength=of=the=injection=grouts=used=for=groutingK=ft=has=also=been=found=that=an=important=parameter=for=the=improvement=of=the=behaviour=of=stone=masonry=strengthened=by=grout= injection=is=the=bond=achieved=between=grout=and=the=in=situ=materialI=and=that=bond=strength=is=not=necessarily=proportional=to=the=compressive=or= tensile=strength=of=the=grout=xPzK=fn=order=to=evaluate=the=effectiveness=Ethe=ability=of=the=grout=to=establish=bonding=between=the=stones=and=the=leaves=of=the=wallF=and=quality=Eperformance=of=the=grout=at= filling=up= the=voidsF=of=the=grout=injection= technique= by= using= different= types= of= grouts= for= the= strengthening= of= and= actual= stone=masonry= buildingI= selected= parts= of= the= stone= masonry= building= were= injected= with= cement= and=combined=cement-lime=groutsK=qhe=walls=of=the=building=from=NV4UI=located=in=the=ruralI=earthquake-prone=area=of=mosočje= in=ploveniaI= were=constructed=with= lime=mortar= and=roughly=shaped=limestone=and= sandstoneI= with= separate= brick= intrusionsK= Based= on= the= criteria= presented= in= x4zI= four= types= of=grouts= were=selected=for= in=situ= application=of= grout= injectionW= two=cement= grouts= designated=`N=and=`OI=and=two=combined=cement-lime=grouts=designated=i`N=and=i`OK=drout=injection=was=performed=on=wall=specimens=“N-`N”I=“O-=i`N”I=“P-i`O”I=“4-`O”K=tall=specimens=were=tested=in=their=existing-ungrouted=state=and=NUM=days=after=strengthening=by=using=several=non-destructiveI=minor=destructive=and=destructive=testsK=tithin=the=scope=of=preliminary=research=workI=laboratory=tests=were=performed=on=cylinders=representing=the=inner=core=of=the=strengthened=wallsK==OK TESTS ON CYiINDERS =fn= order= to= simulate= the= inner= core= of= the= multiple= leaf= stone= masonry= wallsI= cylinders= of= NR= cm=diameter= and= PM= cm= height= were= preparedK= qhe= cylinders= were= gradually= filled= with= limestone=and=sandstoneI=iKeK=PTB=wtK=of=the=fractions=4RLSP=mm=and=POL4R=mmI=ORB=wtK=of=the=fraction=NSLPO=mmI=and=NB= wtK= of= the=fraction=ULNS=mmK=qhe=cylindrical= specimens= were=injected=with= the=grouts=i`NI=i`OI=`N=and=`OK=cor= each=grout=S= test= specimens=were=preparedW=P= for= compressive= tests= and=P= for=tensile= splitting= testsK= At= the= age= of= VM= days= the= cylinders= were= subjected= to= compression= tests=according= to= xRzI= whereas= the= tensile= splitting= strength= tests= were= performed= according= to= xSzK=qhe=results=are=presented=in=cigK=NK==

FigK N=Average=compressive=and=tensile=splitting=strengths=of=cylinders=and=percentage=of=separate=failure=modes=at=tensile=splitting=strength=test=

After=the=tensile=splitting=test=had=been=performedI=the=cross-sections=of=the=specimens=were=inspectedK=ln =averageI =the =area =of =stone =represented =about =SUBI =and =the =area =of =grout =POB=of =the =total =cross-sectionK=qhe=results=presented=in=cigK=N=show=that=the=prevailing=mode=of=failure=by=tensile=splitting=test=was=that=of=the=bond=between=the=stones=and=the=groutI=regardless=the=type=of=used=groutI=and=that=better=bonding=was=achieved=in=case=of=cement=groutsK=qhe=compressive=and=tensile=splitting=strengths=were=greater=in=case=of=the=cement=grouted=cylinders=compared=to=the=cement-lime=specimensK==PK EVAiUATION OF QUAiITY OF GROUT INgECTION BY NDT TESTS =qhree=kaq= techniques=were=used=for=determining=the=quality=of=grout= injectionW=dmo=measurementsI=sonic=pulse=tests=and=thermo-graphic=measurementsK=dmo=measurements=are=based=on=the=emission=and=

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OR4S=

reflection= of= very= short= electromagnetic= impulses= by= an= antenna= systemK= oeflection= of= the= emitted=impulses=occurs=at=the=interfaces=between=materials=with=different=permittivities=or=conductivitiesI=such=as=the=interface=between=air=and=the=building=material=or=voidsK=Because=the=propagation=velocity=and=the=signal=penetration=depend=on=the=electric=and=dielectric=propertiesI=the=boundaries=between=different=materials =can =be =distinguishedK =jeasurements =were =performed =with =a =vertical =E“N-`N”I =“4-`O”F =and =a=horizontal=E“O-i`N”I=“P-i`O”F=arrangement=of=dmo=profiles=at=centre-to-centre=distances=of=PM=cmI=before= and= after= grout= injectionK= qhe= comparison= of= dmo= profiles= before= and= after= grout= injection=shows=that=very=good=penetration=of=the=grout=into=the=voids=of=the=walls=was=achievedK=As=an=exampleI=the=dmo=profiles=performed=on=the=wall=specimens=“O-i`N”=and=“P-i`O”=are=shown=in=cigure=OK=qhe=blue=and=pink=stripes=measured=before=injection=represent=the=electromagnetic=anomaliesI=iKeK=the=voidsI=which=become=blurred=after=grout=injectionK=crom=the=cigK=OI=also=the=position=of=chimney=flue=can=be=distinguished=Elarger=anomaly=located=at=the=middle=of=the=dmo=profiles=which=was=visible=also=after=grout=injectionFK==

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FigK O=eorizontal=dmo=profiles=mP-mS=on=the=walls=O-i`N=and=P-i`O=at=height=TM-NSM=cm=in=intervals=of=PM=cm=before=EleftF=and=after=grout=injection=ErightF=

=ponic=pulse=test=is=based=on=the=generation=of=sonic=impulses=at=a=selected=point=of=the=structureK=Based=on=the=time=that=the=impulse=takes=to=cover=the=distance=between=the=transmitter=and=the=receiverI=the=quality=and=homogeneity=of= the=tested=wall=can=be=determinedK=ponic=pulse=velocity=test=was=used=to=evaluate=the=quality=of=the=grout=injection=technique=at=the=position=of=flat-jack=testK=eigher=pulse=sonic=velocities= were= measured= after= grout= injection= EcigK= PFK= qhe= mean= value= of= pulse= sonic= velocity=measured= before= grout= injection= amounted= to= NNPO= mLsI= and= increased= to= OMUO= mLs= after= grout=injectionK=qhe=individual=values=before=grout= injection=were=between=RSS=and=NSPS=mLsI=whereas= the=values=obtained=after=grout=injection=mainly=ranged=between=NP4P=and=PMMM=mLsK=oesults=showI=that=the=voids=had=been=successfully=filledK==

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FigK P=ponic=test=velocities=measured=at=the=position=of=flat-jack=test=before=EleftF=and=after=grout=injection=ErightF==qhermo-graphic=measurements=are=usually=used=for=detecting=hidden=mistakes= in=building=envelopesI=but=nevertheless=in=the=case=being=studied=the=method=was=successfully=applied=in=the=monitoring=of=the=quality= of= the=grout= injectionK= qhermo-graphical= measurements= made= it= possible= to= identify= the=wall=areas=with=an=increased=surface=temperature=during=a=given=time=interval=after=injection=whenI=because=of=the=hydration=processI=heat=was=releasedK=ft=has=to=be=emphasized=that=the=measured=temperature=of=the=wall=depends=not=only=on=the=hydration=but=also=on=the=external=temperatureK=qhis=is=why=the=results=need=to=be=interpreted=with=knowledge=of= the=external= temperatures=at=the=time=of=measurementI= and=

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OR4T=

a=comparison=of= the=measured=temperatures=between= the= injected=and=non-injected=parts=of= the=wallK=qhe=results=of=thermo-graphic=measurements=performed=on=the=wall=N-`N=OU=hours=and=NM=days=after=grout=injection=are=presented=in=cigK=4K==

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FigK Q=qhermo-graphic=measurements=of=the=wall=N-`N=OU=hours=EmiddleF=and=NM=days=ErightF=after=grouting===

ft= can=be=seen=that= the=greatest= temperature=difference=between=the=injected=and=non-injected=areas=of=the= wall= N-`N= was= measured= OU= hours= after= injection= and= reached= Δq=Z=4°`I= with= an= outside=temperature=of=OM°`K=NM=days=after= injection=the=temperature=difference=between=the= injected=and=the=non-injected=area=was=Δq=Z=O°`K=lbtained=results=showed=high=potential=of=this=measuring=technique=for=monitoring=the=quality=of=grouting=by=cement=injection=groutsK==QK EVAiUATION OF MORPHOiOGY AND MECHANICAi PROPERTIES

OF THE WAiiS BY MDT TESTS =qexture=and=morphology=of= the=walls= was= evaluated= with= the=help= of= surface=and= in-depth=probingK=Brick=linings=EcigK=R=leftF=which=we=have=sought=to=avoid=when=selecting=representative=parts=of=wall=for=shear=testI=were=present=at=some=window=and=door=openingsK=ft=was=found=that=the=walls=had=been=built= with= lime= mortar= and= roughly= shaped= limestone= and= sandstoneI= with= separate= brick= intrusionsK=Although= the= walls= were= constructed= with= two= leafs= without= an= explicit= inner= coreI= depth= probing=confirmed= the= considerable= presence= of= voids= EcigK= R= rightF= and= therefore= the= relatively= high=injectability=of=the=wallsK===

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FigK R=qexture=and=morphology=of=tested=walls=at=window=opening=EleftF=and=at=the=central=part=of=the=wall=ErightF==qhe=morphology=of=the=walls=was=further=examined=on=cross=sections=after=cutting=out=the=specimens=for= the=shear= testK=qhe=walls= of= analysed=building=had= two=leaves= with=simple=connections= made=by=occasionally=overlapping=stonesK=qhe=analysed=walls=had=approximately=NM=B=of=voidsK=qhe=latter=was=calculated=for= the= location=O-i`NI= taking= into=account= the=consumption=of= grout= during= the= injection=procedure= and= the= injected=volume=of= the=wall=which=was= vertically= limited=by=a= door= opening=and=a=chimney=flueI=and=horizontally=by=a=solid=foundation=structure=underneath=and=an=o`=slab=on=topK=fn=order =to =determine =the =deformability =characteristics =of =the =tested =walls =before =and =after =injectionI =

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OR4U=

a=double=flat=jack=test=was=performedK=qhe=tested=part=of=the=wall=was=injected=with=cement=grout=`OK=qwo=parallel=cuts=were=made=at=a=distance=of=RM=cmK=A=thin=flat-jack=was=placed=in=each=of=the=cutsI=and=the=oil=pressure=operating=the=jack=was=gradually=increasedK=isaq`s=placed=between=the=two=cuts=made=it=possible=to=monitor=the=vertical=and=lateral=deformations=during=the=testK=qhe=results=of=the=flat=jack=tests=are=presented=in=cigK=SK===

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FigK S=pet=up=of=the=measuring=equipment=and=results=of=the=double=flat-jack=test=before=EaboveF=and=after=grout=injection=by=cement=grout=`O=EbelowF=

=An= elastic= modulus= b= of=TUR= jma= was= obtained= for= the=ungrouted=stateK= blastic= modulus= for= grout=injected= state=amounted= to=NRMT= jmaK= `onsidering= the=course=of= the= slope= of= the= stress-strain=curve=obtained =from=flat =jack =testsI =an =estimation =of =the =compressive =strength =of =the =wall =before =and =after =grout= injection= was= madeK= `onsequently= values= of= fco=Z=NKTR=jma= for= the= non-injected= walls= and=fcc=Z=OKRM=jma=for=the=walls=injected=with=cement=grout=`O=were=obtainedK=`ompressive=strength=of=the=wall=in=case=of=using=lime-cement=grout=was=roughly=estimated=at=fclc=Z=OKMM=jmaK==RK FORMATION OF CRACKS AND DEFORMATION SHAPE OF THE WAii

SPECIMENS AT DT SHEAR TEST =qhe=procedure=and=detailed=results =of =the=shear =characteristics =of =walls =obtained=by=in=situ =shear =test =are=presented= in=xTzK=auring= the=execution=of=shear= testI=cracks= that= were=formed=on=wall=specimens=were=monitoredK=Based=on=the=results=obtained=by=three=horizontal=and=two=vertical=isaq`sI=also=the=final=deformation=shape=of=wall=specimens=was=determinedK=cormed=cracks=by-passed=solid=built=areas=Eareas=where=solid=stones=were=present=at=a=major=part=of=the=wall’s=cross-sectionF=and=were=more=likely=to=be=formed=on=weaker=areas=where=voids=or=weaker=materials=such=as=brick=or=mortar=were=presentK=After= the= injection= of= groutI= cracks= were= more= likely= to= be= formed= on= originally= solid= built= areas=without= voids= that= were= not= injectableI= rather= than= in= highly= injectable= areas= where= good= bonding=

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OR4V=

between=the=stones=and=the=grout=was=achievedK=cormation=of=the=cracks=and=the=deformation=shape=of=the=non-injected=wall=„S”=is=shown=in=cigK=TK===

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FigK T=cormation=of=cracks=by=shear=test=and=deformation=shape=of=wall=“S”==oesponse=of=the=upper=and=lower=part=of=the=wall=„S”I=that=is=the=measured=drift=and=the=distribution=of=the= formed=cracksI= was= similarK=qhe= first= crack=was= recorded= in= the= tensioned=zone=by= the=absolute=displacement=of=NKR=mmK=By=increasing=the=imposed=displacementI=shear=cracks=formed=simultaneously=in=lower=and=upper=partK=qhe=test=was=concluded=at=absolute=displacement=of=NOKM=mm=where=the=shear=mechanism= was= almost= completely= established=and=the=maximum= lateral= load= was= already=attainedK=qhe=final=drift=amounted=to=MKUVB=in=the=case=of= the=upper=and=MKURB=in=the=case=of= the= lower= wall=elementK=`oring=and=depth=probing=EcigK=UF=revealed=that=the=wall=was=mostly=built=out=of=stones=with=separate=brick=inclusions=and=considerable=amount=of=mortar=and=voidsK===

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FigK U=Borehole=and=in-depth=probing=at=the=lower=half=of=the=wall=“S”==cormation=of=the=cracks=and=the=deformation=shape=of=the=wall=„O-i`N”=injected=by=cement=lime=grout=i`N=is=shown=in=cigK=VK===

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FigK V=cormation=of=cracks=by=shear=test=and=deformation=shape=of=wall=O-i`N=

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ORRM=

qhe= first= cracks= of= the= wall= „O-i`N”= were= formed= in= the= central= tensioned= part= at= absolute=displacement= of=NKM-NKR= mmK=By= increasing= the= imposed=displacementI= shear= cracks= were=formed=at=first =on =the =lower =and =than =also =on =the =upper =wall =specimenK =qhe =test =was =concluded =due =to =local =buckling= of= weaker= area= in= the= lower= wall= element= which= could= result= in= fragile= failure= of= the= test=specimenK=At=the=same=time=also=the=maxumum=lateral=load=was=attainedK=qhe=final=drift=amounted=to=MKNVB=in=the=case=of=lower=and=MKOSB=in=the=case=of=upper=wall=elementI=which=is=considerably=lower=value=if=compared=to=the=non-injected=wall=specimenK=`ore=driled=by=the=shear=crack=of=the=upper=wall=element =revealed =that =this =was =a =solid =built =area =that =was =by-passed =by =the =formed =crackK =aepth =probing=executed=across=the=shear=crack=of=the=lower=wall=specimen=showed=that=this=was=the=area=built=with= smaller= stones= and= larger= amount= of= mortar= without= voids= EcigK= NM= rightFK= puch= composition=continued= in= the=grey=hatched=area= EcigK= VFI= where= the= local=buckling=occuredI= because=of= which= the=test=was=stoppedK===

FigK NM=`ore=from=the=upper=and=in-depth=probing=at=the=bottom=part=of=the=wall=O-i`N=

=SK THE INFiUENCE OF GROUT TYPE ON THE MECHANICAi PROPERTIES

OF INgECTED CYiINDERS AND WAiiS =qhe=results=of=shear=test=of=injected=walls=showedI=that=the=behaviour=of=the=wall=after=grout=injection=is=significantly= influenced= by= the= injection’s= grout= ability= to= establish= a= good= bond= between= separate=stonesI= the=mortar= and=the=outer= leaves=of= the=wallK= An=obvious=distinction=between=related=types=of=grouts=EcementLcement-lime=groutsF=was=evident=both=in=the=case=of=compressive=and=tensile=splitting=strength=tests=of=injected=cylindersI=as=well=as=by=the=shear=tests=performed=on=the=walls=EcigK=NNFK=

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FigK NN=`omparison=of=the=average=compressive=and=tensile=splitting=strengths=of=cylinders=and=injection=grouts=with=tensile=strengths=of=the=walls=

=qhe= main= reasons= for= the= considerable= improvement= of= mechanical= properties= of= walls= after= grout=injection=and=different=degree=of=the=improvement=Edepending=on=the=type=of=used=groutF=are=initially=low=mechanical=properties=of=the=existent=mortar= ENKNT=jmaF=and=relatively=high=percentage=of=voids=Earound=NMBFK=qhe=behaviour=of=the=walls=after=grout=injection=was=no=longer=dependent=solely=on=the=properties=of=existent=materials=EmortarI=stonesI=brick=intrusions=and=the=adhesion=among=themF=and=the=morphology= of= the= wallsI= but= also= on= the= ability= of= the= injection= grout= to= assure=an= adequate=bond=between= separate=stones= and= leaves= of= the=wallK= ft= can=be=concluded=that= in= the= case=of=walls=under=consideration= Elow= initial= mechanical= propertiesI= high= percentage= of= voidsFI= shear= characteristics= of=walls=Etensile=strength=and=stiffnessF=depend=significantly=on=the=grout’s=ability=to=achieve=a=solid=bond=between=the=stones=and=the=leaves=including=the=strength=and=stiffness=of=the=grout=itselfK=

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ORRN=

TK CONCiUSION =mresented= work= aimed= to= evaluate= the= efficiency= of= strengthening= by= means= of= grout= injection=performed= on=an=actual= stone= masonry=buildingK= At= the= same= timeI= the= objective= was= to= assess= the=usefulness= of= diferent= investigation= techniques= in= determining= the= quality= and= effectiveness= of= this=strengthening=techniqueK==dmo=and=sonic=test=methods=have=shown=to=be=reliable=kaq=techniques=for=evaluation=of=the=quality=of=grout=injectionK=Another=effective=method=for=monitoring=of=the=quality=of=grout=injectionI=particularly=in=case=of=cement=groutsI=is=thermographyK=bxamination=of=the=drilled=cores=gave=a=clearer=picture=of=the= quality= of= grout= injection= and= the= achieved= bond= between= the= stonesI= the= lime= mortar= and= the=injected=groutK=qhe=formation=of=the=cracks=by=shear=test=was=in=good=correlation=with=the=morphology=EinjectabilityF=of=the=wall=areasK=Before=groutingI=the=pattern=of=cracks=by-passed=solid=built=areas=and=was= more= likely= to= be= formed= on= weaker= areas= built= with= weaker= materials= or= where= voids= were=presentK=After= the= injection=of=groutI= cracks= were=more= likely= to=be=formed=on=originally=solid=built=parts=that=were=not=injectableI=rather=than=in=highly=injectable=areas=where=good=bonding=between=the=stones=and=the=grout=was=achievedK=qhe=usage=of=several=kaqI=jaq=and=aq=investigation=techniques=has=proven=to=be=a=an=appropriate=aproachI=since=it=enables=more=reliable=assessment=of=the=quality=and=effectiveness=of=grout=injectionK==qhe=compressive=and= tensile=strengths=of=cylinders=representing=the= inner=core=of=strengthened=stone=masonry= were=higher= in= case=of= the=cement= grouted=cylinders= compared=to= the=cement-lime=grouted=onesK= oegardless= of= the= type=of=grout= used=for= groutingI= the=prevailing=mode=of= failure= in= the= tensile=splitting= test= was= always= that= of= the=bond=between= the= stones= and= the= groutK= qhe=adhesive= strength=achieved= between= stones= and= injection= grout= obviously= had= the= most= important= influence= on= tensile=splitting=strength=of=cylindersK=oesults=of=in=situ=shear=test=showed=that=by=analysed=type=of=walls=which=exhibited=rather=low=mechanical=properties=and=quite=high=injectability=in=their=existentI=unstrengthened=stateI= shear= characteristics= Etensile= strength= and= stiffnessF= depend= significantly= on= the= type= and=properties=of=injection=grout=used=for=strengtheningK==ACKNOWiEDGEMENTS =qhe=research=was=partially=supported=by=the=jinistry=of=pcience=and=qechnology=and=the=jinistry=of=the= bnvironment= and= ppatial= mlanningI= and= was= also= partly= financed= by= the= buropean= rnionDs=`ohesion=cund=through=the=plovenian=qechnology=Agency=qfA=and=mbombqrAqb=dA=O44OOVK= REFERENCES xNz qoumbakari=bbKI=san=demert=aKI=qassios=qmKI=sintzileI=bK=EOMM4F=bxperimental=investigation=and=

analytical= modeling= of= the= effect= of= injection= grouts= on= the= structural= behaviour= of= three-leaf=masonry=wallsK=fnW=ptructural Analysis of eistorical ConstructionsI=madovaI=ftalyW=TMT-TNTK

xOz saluzzi=joKI=da=morto=cKI=jodena=`K=EOMM4F=Behavior=and=modeling=of=strengthened=three-leaf=stone=masonry=wallsK=ofiEj jater ptructI=PTW=NU4-NVOK=

xPz sinzileou=bK=EOMMSF=drouting=of=three-leaf=stone=masonryW=qypes=of=groutsI=mechanical=properties=of= masonry=before=and=after= groutingK= fnW= ptructural Analysis of eistorical ConstructionsI= kew=aelhiI=fndiaW=4N-RUK=

x4z rranjek= jKI= Žarnić= oKI= Bokan-Bosiljkov= sKI= Bosiljkov= sK= EOMNMF= mroblems= related= to= grout=injection= of= heritage= buildings= wallsK= fnW= mrocK of the Uth fnternational jasonry ConferenceI=aresdenI=dermanyW=NMRR-NMS4K=

xRz pfpq= bk= NOPVM-P= EOMMOF= qesting= hardened= concrete= –= mart= PW= `ompressive= strength= of= test=specimensK=plovenian=fnstitute=for=ptandardizationI=ijubljanaI=ploveniaI=pK=NRK=

xSz pfpq=bk=NOPVM-S= EOMMNF=qesting= hardened=concrete=–=mart= SW=qensile= splitting= strength=of= test=specimensK=plovenian=fnstitute=for=ptandardizationI=ijubljanaI=ploveniaI=pK=NMK=

xTz rranjek= jKI= Bosiljkov= sKI= Žarnić= oKI= Bokan-Bosiljkov= sK= EOMNNF= fn= situ= tests= and= seismic=assessment=of=a=stone-masonry=buildingK=ofiEj jater ptructI alfW=NMKNSNTLsNNROT-MNN-VUM4-zW=pK=NVK=